... from the database. You can customize the behavior of this fetching with a fetch mode , making it more efficient or even blocking it. Use QuerySet.fetch_mode() to set the fetch mode for m ... odel instances fetched by a QuerySet : from django.db import models books = Book . objects . fetch_mode ( models . FETCH_PEERS ) Fetch modes ap ... rs Fields deferred with QuerySet.defer() or QuerySet.only() ジェネリックリレーション（汎用リレーション） Django copies the fetch mode of an instance to any related objects it fetches, so the mode applies to a whole tree of relationships, not just the ... ... from the database. You can customize the behavior of this fetching with a fetch mode , making it more efficient or even blocking it. Use QuerySet.fetch_mode() to set the fetch mode for m ... odel instances fetched by a QuerySet : from django.db import models books = Book . objects . fetch_mode ( models . FETCH_PEERS ) Fetch modes ap ... rs Fields deferred with QuerySet.defer() or QuerySet.only() ジェネリックリレーション（汎用リレーション） Django copies the fetch mode of an instance to any related objects it fetches, so the mode applies to a whole tree of relationships, not just the ... ... highly recommend , and only officially support, the latest release of each series. What's new in Django 6.1 ¶ Model field fetch modes ¶ The on-demand fetching behavior of model fields is now configurable with fetch modes . These modes allow you to co ... ntrol how Django fetches data from the database when an unfetched field is accessed. Django provides three fetch modes: FETCH_ONE , the default, ... fetches the missing field for the current instance only. This mode represents Django's existing behavior. FETCH_PEERS fetches a missing field for all instances that came from the same QuerySet . This mode works like an on-demand prefe ... ... highly recommend , and only officially support, the latest release of each series. What's new in Django 6.1 ¶ Model field fetch modes ¶ The on-demand fetching behavior of model fields is now configurable with fetch modes . These modes allow you to co ... ntrol how Django fetches data from the database when an unfetched field is accessed. Django provides three fetch modes: FETCH_ONE , the default, ... fetches the missing field for the current instance only. This mode represents Django's existing behavior. FETCH_PEERS fetches a missing field for all instances that came from the same QuerySet . This mode works like an on-demand prefe ... ... e until it is reloaded . モデルの読み込みをカスタマイズする ¶ classmethod Model. from_db ( db , field_names , values , * , fetch_mode = None ) [ソース] ¶ from_db() メソッドを使うと、データベースから読み込むときのモデルインスタンス作成をカスタマイズでき ... won't appear in field_names . In that case, assign a value of django.db.models.DEFERRED to each of the missing fields. The fetch_mode argument contains the fetch mode of the query that loaded the instance, or None if it was loaded outside of a query. ... ing the new model, the from_db() method must set the adding and db flags in the new instance's _state attribute, and, when fetch_mode is not None , its fetch_mode attribute. 以下はデータベースから読み出されたフィールドの初期値をどのように保存しているの ... ... the ticket claimed, create a branch for your work, replacing TicketNumber with the actual Trac ticket number: / $ git fetch upstream $ git checkout -b ticket_TicketNumber upstream/main ...\> git fetch upstream ...\> git checkout -b ticket_TicketN ... . Run the following, replacing PRNumber and TicketNumber with the actual pull request and Trac ticket numbers: / $ git fetch upstream pull/PRNumber/head:ticket_TicketNumber $ git checkout ticket_TicketNumber $ git push origin ticket_TicketNumber . ... ..\> git fetch upstream pull/PRNumber/head:ticket_TicketNumber ...\> git checkout ticket_TicketNumber ...\> git push origin ticket_Ticket ... ... the ticket claimed, create a branch for your work, replacing TicketNumber with the actual Trac ticket number: / $ git fetch upstream $ git checkout -b ticket_TicketNumber upstream/main ...\> git fetch upstream ...\> git checkout -b ticket_TicketN ... . Run the following, replacing PRNumber and TicketNumber with the actual pull request and Trac ticket numbers: / $ git fetch upstream pull/PRNumber/head:ticket_TicketNumber $ git checkout ticket_TicketNumber $ git push origin ticket_TicketNumber . ... ..\> git fetch upstream pull/PRNumber/head:ticket_TicketNumber ...\> git checkout ticket_TicketNumber ...\> git push origin ticket_Ticket ... ... e until it is reloaded . モデルの読み込みをカスタマイズする ¶ classmethod Model. from_db ( db , field_names , values , * , fetch_mode = None ) [ソース] ¶ from_db() メソッドを使うと、データベースから読み込むときのモデルインスタンス作成をカスタマイズでき ... won't appear in field_names . In that case, assign a value of django.db.models.DEFERRED to each of the missing fields. The fetch_mode argument contains the fetch mode of the query that loaded the instance, or None if it was loaded outside of a query. ... ing the new model, the from_db() method must set the adding and db flags in the new instance's _state attribute, and, when fetch_mode is not None , its fetch_mode attribute. 以下はデータベースから読み出されたフィールドの初期値をどのように保存しているの ... ... doing many database queries, when only one is needed. Below are some techniques to combine queries for efficiency. Use the FETCH_PEERS fetch mode ¶ Use the FETCH_PEERS fetch mode to make on-demand field access more efficient with bulk-fetching. Enable ... it for all usage of your models with a custom manager . Using this fetch mode is easier than declaring fields to fetch with select_related() or prefetch_related() , especially when it's hard to p ... redict which fields will be accessed. QuerySet.select_related() や prefetch_related() を使用する ¶ When the FETCH_PEERS fetch mode is not appropriate or efficient enough, use select_related() and pr ... ... doing many database queries, when only one is needed. Below are some techniques to combine queries for efficiency. Use the FETCH_PEERS fetch mode ¶ Use the FETCH_PEERS fetch mode to make on-demand field access more efficient with bulk-fetching. Enable ... it for all usage of your models with a custom manager . Using this fetch mode is easier than declaring fields to fetch with select_related() or prefetch_related() , especially when it's hard to p ... redict which fields will be accessed. QuerySet.select_related() や prefetch_related() を使用する ¶ When the FETCH_PEERS fetch mode is not appropriate or efficient enough, use select_related() and pr ... 2026年10月08日